{"id":"https://openalex.org/W1964858495","doi":"https://doi.org/10.1007/bf01200064","title":"Three ? P 2 -complete problems in computational learning theory","display_name":"Three ? P 2 -complete problems in computational learning theory","publication_year":1991,"publication_date":"1991-09-01","ids":{"openalex":"https://openalex.org/W1964858495","doi":"https://doi.org/10.1007/bf01200064","mag":"1964858495"},"language":"en","primary_location":{"id":"doi:10.1007/bf01200064","is_oa":false,"landing_page_url":"https://doi.org/10.1007/bf01200064","pdf_url":null,"source":{"id":"https://openalex.org/S193995496","display_name":"Computational Complexity","issn_l":"1016-3328","issn":["1016-3328","1420-8954"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320186","host_organization_name":"Birkh\u00e4user","host_organization_lineage":["https://openalex.org/P4310320186","https://openalex.org/P4310319900"],"host_organization_lineage_names":["Birkh\u00e4user","Springer Science+Business Media"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Computational Complexity","raw_type":"journal-article"},"type":"article","indexed_in":["crossref"],"open_access":{"is_oa":false,"oa_status":"closed","oa_url":null,"any_repository_has_fulltext":false},"authorships":[{"author_position":"first","author":{"id":"https://openalex.org/A5113600199","display_name":"Ker\u2010I Ko","orcid":null},"institutions":[{"id":"https://openalex.org/I1327163397","display_name":"State University of New York","ror":"https://ror.org/01q1z8k08","country_code":"US","type":"education","lineage":["https://openalex.org/I1327163397"]},{"id":"https://openalex.org/I59553526","display_name":"Stony Brook University","ror":"https://ror.org/05qghxh33","country_code":"US","type":"education","lineage":["https://openalex.org/I59553526"]}],"countries":["US"],"is_corresponding":true,"raw_author_name":"Ker-I Ko","raw_affiliation_strings":["Department of Computer Science, State University of New York, 11794, Stony Brook, NY","Stony Brook University"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, State University of New York, 11794, Stony Brook, NY","institution_ids":["https://openalex.org/I59553526","https://openalex.org/I1327163397"]},{"raw_affiliation_string":"Stony Brook University","institution_ids":["https://openalex.org/I59553526"]}]},{"author_position":"last","author":{"id":"https://openalex.org/A5050112080","display_name":"Wen-Guey Tzeng","orcid":"https://orcid.org/0000-0002-0441-5006"},"institutions":[{"id":"https://openalex.org/I59553526","display_name":"Stony Brook University","ror":"https://ror.org/05qghxh33","country_code":"US","type":"education","lineage":["https://openalex.org/I59553526"]},{"id":"https://openalex.org/I1327163397","display_name":"State University of New York","ror":"https://ror.org/01q1z8k08","country_code":"US","type":"education","lineage":["https://openalex.org/I1327163397"]}],"countries":["US"],"is_corresponding":false,"raw_author_name":"Wen-Guey Tzeng","raw_affiliation_strings":["Department of Computer Science, State University of New York, 11794, Stony Brook, NY","Dept. of Computer Science, State University of New York, Stony Brook,"],"affiliations":[{"raw_affiliation_string":"Department of Computer Science, State University of New York, 11794, Stony Brook, NY","institution_ids":["https://openalex.org/I59553526","https://openalex.org/I1327163397"]},{"raw_affiliation_string":"Dept. of Computer Science, State University of New York, Stony Brook,","institution_ids":["https://openalex.org/I1327163397"]}]}],"institutions":[],"countries_distinct_count":1,"institutions_distinct_count":2,"corresponding_author_ids":["https://openalex.org/A5113600199"],"corresponding_institution_ids":["https://openalex.org/I1327163397","https://openalex.org/I59553526"],"apc_list":{"value":2290,"currency":"EUR","value_usd":2890},"apc_paid":null,"fwci":0.5383,"has_fulltext":false,"cited_by_count":25,"citation_normalized_percentile":{"value":0.7108603,"is_in_top_1_percent":false,"is_in_top_10_percent":false},"cited_by_percentile_year":{"min":89,"max":95},"biblio":{"volume":"1","issue":"3","first_page":"269","last_page":"310"},"is_retracted":false,"is_paratext":false,"is_xpac":false,"primary_topic":{"id":"https://openalex.org/T12072","display_name":"Machine Learning and Algorithms","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},"topics":[{"id":"https://openalex.org/T12072","display_name":"Machine Learning and Algorithms","score":0.9998999834060669,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11567","display_name":"semigroups and automata theory","score":0.9965999722480774,"subfield":{"id":"https://openalex.org/subfields/1703","display_name":"Computational Theory and Mathematics"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}},{"id":"https://openalex.org/T11269","display_name":"Algorithms and Data Compression","score":0.994700014591217,"subfield":{"id":"https://openalex.org/subfields/1702","display_name":"Artificial Intelligence"},"field":{"id":"https://openalex.org/fields/17","display_name":"Computer Science"},"domain":{"id":"https://openalex.org/domains/3","display_name":"Physical Sciences"}}],"keywords":[{"id":"https://openalex.org/keywords/mathematics","display_name":"Mathematics","score":0.7039641737937927},{"id":"https://openalex.org/keywords/combinatorics","display_name":"Combinatorics","score":0.6422683596611023},{"id":"https://openalex.org/keywords/nondeterministic-algorithm","display_name":"Nondeterministic algorithm","score":0.6227891445159912},{"id":"https://openalex.org/keywords/existential-quantification","display_name":"Existential quantification","score":0.6203739047050476},{"id":"https://openalex.org/keywords/discrete-mathematics","display_name":"Discrete mathematics","score":0.5557882189750671},{"id":"https://openalex.org/keywords/decision-problem","display_name":"Decision problem","score":0.47087228298187256},{"id":"https://openalex.org/keywords/np","display_name":"NP","score":0.4222080111503601},{"id":"https://openalex.org/keywords/turing-machine","display_name":"Turing machine","score":0.3540423512458801},{"id":"https://openalex.org/keywords/algorithm","display_name":"Algorithm","score":0.14991077780723572}],"concepts":[{"id":"https://openalex.org/C33923547","wikidata":"https://www.wikidata.org/wiki/Q395","display_name":"Mathematics","level":0,"score":0.7039641737937927},{"id":"https://openalex.org/C114614502","wikidata":"https://www.wikidata.org/wiki/Q76592","display_name":"Combinatorics","level":1,"score":0.6422683596611023},{"id":"https://openalex.org/C176181172","wikidata":"https://www.wikidata.org/wiki/Q3490301","display_name":"Nondeterministic algorithm","level":2,"score":0.6227891445159912},{"id":"https://openalex.org/C136979486","wikidata":"https://www.wikidata.org/wiki/Q773483","display_name":"Existential quantification","level":2,"score":0.6203739047050476},{"id":"https://openalex.org/C118615104","wikidata":"https://www.wikidata.org/wiki/Q121416","display_name":"Discrete mathematics","level":1,"score":0.5557882189750671},{"id":"https://openalex.org/C115988155","wikidata":"https://www.wikidata.org/wiki/Q3262192","display_name":"Decision problem","level":2,"score":0.47087228298187256},{"id":"https://openalex.org/C91331118","wikidata":"https://www.wikidata.org/wiki/Q628036","display_name":"NP","level":4,"score":0.4222080111503601},{"id":"https://openalex.org/C29248071","wikidata":"https://www.wikidata.org/wiki/Q163310","display_name":"Turing machine","level":3,"score":0.3540423512458801},{"id":"https://openalex.org/C11413529","wikidata":"https://www.wikidata.org/wiki/Q8366","display_name":"Algorithm","level":1,"score":0.14991077780723572},{"id":"https://openalex.org/C45374587","wikidata":"https://www.wikidata.org/wiki/Q12525525","display_name":"Computation","level":2,"score":0.0}],"mesh":[],"locations_count":1,"locations":[{"id":"doi:10.1007/bf01200064","is_oa":false,"landing_page_url":"https://doi.org/10.1007/bf01200064","pdf_url":null,"source":{"id":"https://openalex.org/S193995496","display_name":"Computational Complexity","issn_l":"1016-3328","issn":["1016-3328","1420-8954"],"is_oa":false,"is_in_doaj":false,"is_core":true,"host_organization":"https://openalex.org/P4310320186","host_organization_name":"Birkh\u00e4user","host_organization_lineage":["https://openalex.org/P4310320186","https://openalex.org/P4310319900"],"host_organization_lineage_names":["Birkh\u00e4user","Springer Science+Business Media"],"type":"journal"},"license":null,"license_id":null,"version":"publishedVersion","is_accepted":true,"is_published":true,"raw_source_name":"Computational Complexity","raw_type":"journal-article"}],"best_oa_location":null,"sustainable_development_goals":[],"awards":[],"funders":[{"id":"https://openalex.org/F4320306076","display_name":"National Science Foundation","ror":"https://ror.org/021nxhr62"}],"has_content":{"grobid_xml":false,"pdf":false},"content_urls":null,"referenced_works_count":28,"referenced_works":["https://openalex.org/W1509542583","https://openalex.org/W1965415591","https://openalex.org/W1970089350","https://openalex.org/W1996184580","https://openalex.org/W1997178577","https://openalex.org/W1998084650","https://openalex.org/W2007431032","https://openalex.org/W2007464118","https://openalex.org/W2011039300","https://openalex.org/W2015772170","https://openalex.org/W2019363670","https://openalex.org/W2020114845","https://openalex.org/W2020240363","https://openalex.org/W2022124343","https://openalex.org/W2028891561","https://openalex.org/W2033323875","https://openalex.org/W2036265926","https://openalex.org/W2046429891","https://openalex.org/W2056660085","https://openalex.org/W2057914679","https://openalex.org/W2065251436","https://openalex.org/W2093717447","https://openalex.org/W2117049614","https://openalex.org/W2139709458","https://openalex.org/W2154952480","https://openalex.org/W2799004609","https://openalex.org/W3152126650","https://openalex.org/W4213214460"],"related_works":["https://openalex.org/W1531056015","https://openalex.org/W4233053549","https://openalex.org/W1505947458","https://openalex.org/W2035025857","https://openalex.org/W2024358852","https://openalex.org/W1563292958","https://openalex.org/W236032","https://openalex.org/W3011865185","https://openalex.org/W2031805167","https://openalex.org/W4387304407"],"abstract_inverted_index":null,"counts_by_year":[{"year":2025,"cited_by_count":1},{"year":2023,"cited_by_count":1},{"year":2020,"cited_by_count":1},{"year":2019,"cited_by_count":1},{"year":2018,"cited_by_count":1},{"year":2014,"cited_by_count":1}],"updated_date":"2025-11-06T03:46:38.306776","created_date":"2025-10-10T00:00:00"}